Fire ants are a formidable pest that can inflict severe pain on unsuspecting individuals. Just ask anyone who has been unfortunate enough to get repeatedly stung by a swarm of this invasive species. Fire ants are found throughout the southern states and inhabit a variety of landscapes, including golf courses – which offer a favorable environment for them with the moist soil and low-cut turf. In fact, fire ants are so common on golf courses that they are mentioned in the Rules of Golf as a dangerous animal condition (Rule 16.2). The medical threat of stings, and the unsightly mounds they create, makes controlling fire ants a high priority for any golf course superintendent.
Treatments are most effective when ants are active. This is especially true when using a bait treatment that must be carried back to the colony and shared with other ants. If temperatures are too hot or too cold, the worker ants tasked with finding food will not forage and remain underground, leaving bait granules untouched. Such a scenario is problematic because fresh baits work significantly better than stale baits. A light rain or a few hours baking in the sun on a hot day can render a bait ineffective.
So, when should one apply a bait? Much of fire ant foraging occurs when soil temperatures are between 70-95 degrees Fahrenheit in the upper inch of soil. Therefore, in places like Texas, which can stay warm through October, fall is generally a good time to make a treatment and improve conditions for next season. A good first step before applying the bait treatment is to use some unlaced food to gauge the level of fire ant activity and confirm whether an application is warranted. Fire ants enjoy oily foods, like many Americans, making hot dogs a highly sought-after treat. Simply cut off a small piece of hot dog and place it in an area of suspected fire ant activity. Look for mounds of disturbed soil as these are typically a telltale sign of fire ants. Mark the hot dog with a flag so that it can be easily found and examined later. If fire ants are actively foraging, they should be covering the piece of hot dog in 30 minutes or so. If not, it is advised to hold off on treating until later in the afternoon or on another day when they are more active. As always, it is important to review insecticide labels before making any treatments.
Baits are a great component of an integrated pest management program and can provide roughly 90% suppression when applied correctly. So, before you go to bat against fire ants, make sure to grab a hot dog. It will be a homerun!
Central Region Agronomists:
John Daniels, agronomist – jdaniels@usga.org
Zach Nicoludis, agronomist – znicoludis@usga.org